Step response classification for model-based autotuning via polygonal curve approximation

A model-based autotuning method consists of an identification and a regulator tuning phase. To achieve satisfactory performance and robustness, it is advisable that both phases be tailored a priori to the characteristics of the observed process dynamics. Such characteristics include, but are not limited to, the model structure. For example, overdamped and underdamped models with the same pole-zero structure are parametrised and controlled in different ways. Step response data, that are typically used for the identification phase in the autotuning context, can also be pre-processed to reveal those characteristics. This paper presents a step response classification method suitable for the above purpose. The method is based on a polygonal curve approximation technique for data pre-processing, followed by a neural network classifier. Only normalised I/O data are employed, so that the neural network can be trained off-line with simulated data. Simulation results are reported to show the effectiveness of the proposed classification method in terms of the achievable tuning results.     

S—135钢板热轧工艺研究

S—135钢板是水电站用高强耐磨不锈钢板,既要求强度高、韧性好,又要求耐磨、耐蚀性强,生产难度较大。除我厂外,目前国内尚无其它厂家能够生产这种钢板。该钢板在加热轧制,冷却过程中要解决很多技术难点。我们通过采用特殊的控制轧制和控制冷却工艺,很好地解决了诸多技术难点,使S—135钢板的开发研制取得了成功。为电站用高强度耐磨不锈钢生产提供了宝贵的经验,也为控制轧制及控制冷却技术在中板生产行业的应用起到了积极的推动作用。     

C pm MPPAC for manufacturing quality control applied to the precision voltage reference process

The multiprocess performance analysis chart (MPPAC) based on the process capability index C_pm, called C_pm MPPAC, is developed for analysing the manufacturing quality of a group of processes in a multiple process environment. The C_pm MPPAC conveys critical information of multiple processes regarding the departure of the process and process variability from one single chart. Existing research works on MPPAC are restricted to obtaining quality information from one single sample of each process ignoring sampling errors. The information provided from existing MPPAC charts, therefore, is unreliable and misleading and results in incorrect decisions. In this paper, we consider the natural estimator of C_pm based on multiple samples. Based on the natural estimator of C_pm, we consider the sampling errors by providing an explicit formula with the Matlab program to obtain the estimation accuracy of the C_pm. We tabulate the sampling accuracy of C_pm for sample size determination so that the engineers/practitioners can use it for their in-plant applications. An example of multiple precision voltage reference (PVR) processes is presented to illustrate the applicability of C_pm MPPAC for manufacturing quality control.     

衡阳钢管厂Φ89mm半浮芯棒连轧管机组工艺及设备结构特点

衡阳钢管厂Φ８９ｍｍ半浮芯棒连轧管机组是一种新型机组，其选配的变形工艺路线能很好地适应生产小规格的热轧无缝钢管。本文论述了该机组的工艺及设备结构特点。     

计算机在热处理工艺编制中的应用

利用计算机强大的数据处理功能 ,对热处理工艺中的各种数据进行记录和处理 ,并制成各种图表 ,掌握其中的各种规律。使热处理工艺的编制不再是一种经验积累式的工作 ,而是依照其规律制定一次合格的规范的热处理工艺卡片 ,并为将来计算机工艺自动生成的工作打下基础     

Energy and resources as production factors in process industries

It is shown that, when the mean productivity of some factors, such as energy or materials, is upperly bounded (a condition usually arising in energy production or in the process industries where energy takes part in physico-chemical processes), the production function may not be convex and, under some further conditions, is concave. Consequences of this model on the economics of energy savings are examined, and it is shown that energy savings may be considered at three levels: in the short run, by action on labour factors: in the medium run, by investment and action on labour factors; in the long run, by technological innovation, investment in new technologies and action on labour factors. Empirical findings along these lines are thus confirmed.     

多陀螺自动化测试系统研究

针对动力调谐挠性陀螺大批量生产中存在的性能调试和参数标定工作量大的问题，我们专门研制了一套多陀螺自动化测试系统，该系统主要包括多陀螺真空恒温安装基准体、测控台、计算机程控自动化数据采集和仪器等部分，本文着重介绍该系统的组成原理，设计特点和研制成果。     

《后期制作》实践教学中基于工作过程的教学改革与探索

根据《后期制作》课程的特点,结合学院的课程教学改革项目,对本课程实践教学过程中存在的问题进行剖析,提出实践教学要以工作过程系统化教学理念为指导．阐述从项目课程向工作过程系统化课程发展的主要任务。